Corrosion susceptibility of the nanophases of the Al-based amorphous-nanocrystalline coatings

• Published in: Corrosion science Vol. 223; p. 111474
• Main Authors: Wang, Q., Wang, D.B., Cui, J.P., Li, T.R., Emori, W., Zhang, S.D., Wang, J.Q.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2023
• Subjects: Amorphous-nanocrystalline coating; EIS; Localized corrosion; Passive films; TEM; Passive films; Localized corrosion; Amorphous-nanocrystalline coating; TEM; EIS
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2023.111474

The influence of the size and types of nanophases on the corrosion behavior for Al86Ni6Y4.5Co2La1.5 amorphous-nanocrystalline coatings in a chloride-containing environment were systematically studied. Results revealed that when the two coatings contained only α-Al nanophase with different size, it was the combined effects of the carrier density and the thickness for the passive film that determined the stability of the passive film. Moreover, with the presence of Al-TM and Al-RE nanophases, the origin of localized corrosion on the coating was ascribed to the weak passive film stability on Al-RE nanophase, which was preferentially dissolved by the interaction with chloride ions. [Display omitted] •Corrosion initiation of Al-based ANCs was observed by quasi in-situ TEM.•Cl− induced rapid thinning occurs for the passive film on larger α-Al nanophase.•Origin of localized corrosion for multi-phases contained coating was identified.•The unstable passive film on YAl3 phase was the origin of localized corrosion.